In the interior parts of an automobile formed of a resin molded product, in many cases, a molded product is normally used after being subjected to a post treatment such as coating and lamination of outer layers in order to improve scratch resistance, low gloss property (improving low gloss property is aimed at imparting a molded product with high grade sense or suppressing reflection from the background to the window glass in respect of safety), and to conceal the inferior appearance such as flow marks. Therefore, excellent economy of a resin molded product has not been fully exhibited.
As the material which has excellent scratch resistance, low gloss property and an appearance having a small amount of flow marks, Patent Document 1 discloses a polypropylene-based resin composition. However, this resin composition was insufficient in low gloss property. In addition, due to the use of a high-molecular ethylene α-olefin diene copolymer, this resin composition has poor dispersibility, and hence, paint coat particles are likely to generate on the surface of a molded product. Further, there was a problem that the raw material cost was increased when an ethylene α-olefin diene copolymer is used.
Patent Document 2 discloses a polypropylene-based resin composition with a good appearance having invisible weld or the like having well-balanced rigidity and impact resistance. However, the [η] (tetralin, 135° C.) of an EPR part of block polypropylene used in base polypropylene is 4 to 5.5 (dl/g) and hence, a swell is not generated sufficiently. Therefore, when a resin is injected in a mold, the appearance of a molded product becomes poor due to unstable adhesion of a mold and a resin.
Patent Document 3 discloses a propylene resin composition which has excellent moldability and is capable of forming a molded product with a good appearance (appearance having only a small amount of flow marks, texture). However, this propylene resin composition does not provide sufficient excellent mechanical properties.
Patent Document 4 discloses a propylene resin composition having excellent moldability. In particular, it discloses a propylene resin composition capable of producing a molded product by injection molding which hardly suffers generation of flow marks, exhibits good low gloss property and in which welds are hardly generated. However, this resin composition did not have sufficient scratch resistance.
Patent Document 5 discloses a propylene resin composition which has well-balanced mechanical properties. This resin composition does not have sufficient scratch resistance. In addition, the [η] of an EPR part of block polypropylene used in base polypropylene is relatively high, there is a problem that paint coat particles are likely to generate on the surface of a molded product.